The present invention relates to a DC power supply, and more particularly, to a DC power supply which is so arranged as to an inverse polarity of DC-side voltage derived from a DC main voltage and having a simple construction.
Generally, the conventional type of DC power supply 51, as shown in FIG. 4, is adapted to output a DC high voltage+Vm (for example, 6KV) between a main output terminal p and a ground terminal g, and also, --Vs (for example, --400 V), which is an inverse polarity DC medium voltage, between an inverse polarity side output terminal n and the ground terminal g.
In order to obtain the DC high voltage+Vm as a main voltage, the output voltage Vo of a secondary-side main winding .alpha. of a transformer T is rectified and smoothed by a diode D1 and a capacitor C1.
Also, in order to obtain the inverse polarity DC medium voltage--Vs as an inverse polarity side voltage, the output voltage V1 of the secondary-side side-winding .beta. of the transformer T is rectified and smoothed by a diode D2 and a capacitor C2. It is to be noted that reference character L1 is a main load, and reference character L2 is a side load.
The above-described conventional DC power supply 51 requires a secondary side side-winding .beta. on a transformer T to draw out the inverse polarity side voltage, thus resulting in a larger-sized and higher-priced transformer T.